R: Crash exiting DrScheme

["Maurizio Ferreira" <ferreira@selesta.it>]

Quoting: Matthew Flatt

> I've fixed this problem in the latest source (exp-tagged in CVS), at
> least for the crash I see in Win98.
>
> I don't understand exactly why the crash happens. DrScheme crashes
> *after* it calls _exit(), which is supposed to terminate the program
> without doing anything else. MzScheme also calls _exit().
>
I don't know if this is the case, but sometimes Windows Sends a wm_size
message
to a window even after having sent to it a wm_destroy message.
I'm not sure if this message goes through the normal message queue or not,
but sometimes this happens.
If the routine handling the wm_destroy message removes something needed by
the routine linked to
wm_size, then this could overwrite memory areas, causing  the error, perhaps
several instructions later.
Another thing to look after  is DDE handling (if DDE initialize is called).
again, is it possible that windows sends some dde message to a window even
after having sent a wm_destroy message.
I went crazy about both problems, working in Delphi.

Maurizio